Microsoft has given us plenty of clues on Windows Server 2016. We're
taking a closer look at the new functionality IT admins will be able to
take advantage of in the new Windows Server 2016 Storage Replica
feature.
Microsoft has been busy over the last couple of months spilling the
beans on new features coming in Windows 10 and Windows Server 2016.
Between the annual conference lineup (Build and Ignite) and carefully
timed pre-conference announcements, Microsoft has given us a peek under
the hood of the next version of Windows Server. We're going to take a
look back at some of the key features that have become public over the
last couple of months and dig into why you should care.
Microsoft's Storage Strategy: Storage Replica
With Windows Server 2012 and Windows Server 2012 R2, Microsoft made
strides in its storage game through the introduction of Storage Spaces,
which provides RAID-like capabilities, such as fault tolerance,
striping, and even storage tiers at the software level. Storage Spaces
was a key component in Microsoft's story with the Windows Server 2012
family, providing a storage subsystem which could be automated and
managed in large scale cloud implementations.
The storage team at Microsoft strikes again in Windows Server 2016
with the introduction of Storage Replica. Storage Replica provides
block-level replication between locations and is intended primarily for
disaster prevention, such as the ability to restore service to an
alternate data center with minimal downtime or data loss, or even to
shift services to an alternate site prior to a disaster occurrence such
as a major storm.
Use Cases
A key scenario Microsoft is pushing for with Storage Replica is the
concept of stretch clusters, or clusters which are separated over long
distances geographically. By leveraging Storage Replica, the cluster
storage can be replicated synchronously between sites in order to
minimize downtime due to the loss of a corporate data center.
Microsoft did caution about replacing purpose-built replication
solutions with Storage Replica and stretch clusters. In particular,
services like Active Directory and Exchange Server are built to handle
global replication, and Hyper-V Replica and SQL Server AlwaysOn
Availability Groups are tailored for a specific use case, so Storage
Replication isn't an ideal solution for these scenarios.
Technical Components
Windows Server 2016 supports several replication scenarios within
Storage Replica: Server to Server, Cluster to Cluster, or Stretch
Cluster. Storage Replica uses block-level, volume based replication. SMB
3.1.1 is leveraged, bringing features such as multichannel, RDMA,
encryption, and digital signatures. Database-like transaction logs are
used to manage updates to replicas. As files are updated on the master
volume, the log is appended and synchronized as appropriate depending on
whether synchronous or asynchronous replication is desired.
Flexibility and Management
Storage Replica is volume based, supporting any Windows storage
volume utilizing fixed disks. Any disk fabric is supported (Fibre
Channel, iSCSI, SAS, etc.), but the disk geometry must be the same due
to the replication being block level.
Existing management tools will be able to natively handle Storage
Replica, including Failover Cluster Manager, Windows PowerShell, and
WMI. The ability to manage Storage Replica using native, familiar tools
should ease the implementation process and result in increased
efficiency over third party solutions.
Technical Requirements
Naturally there are some technical requirements for implementing
Storage Replica. First and foremost is the need for Windows Server 2016
Datacenter Edition. Those familiar with Windows Server licensing will
know Datacenter Edition bears the highest cost of any Windows Server
SKU, but also unlocks multiple enterprise features such as raising
processor and memory thresholds as well as allowing for an unlimited
number of guest virtual machines.
Each file server requires a minimum of one 1GbE network connection,
though increased network capabilities are desirable. A minimum of 1Gbps
throughput between servers is required, though a minimum of 8Gbps is
recommended. Additionally, an average of ≤5ms latency between file
servers is necessary.
Due to the network-based nature of Storage Replica, a network
connection between file servers is necessary. Firewall rules allowing
bi-directional ICMP, SMB port 445 (and 5445 for SMB Direct), and port
5985 (WS-MAN) network traffic may be required.
Active Directory is a key requirement of Stretch Clusters with
Storage Replica, though it need not be running on Windows Server 2016.
There
are clear benefits to having the capability to instantly failover
critical services to an alternate site, either prior to or as a result
of a disaster. This sort of functionality is currently available from a
variety of vendors, but having it baked into the Windows Server platform
will add power and flexibility to existing services. With the potential
for savings as a result of reduced licensing costs or hardware
purchases, the end-to-end storage solutions offered in Windows Server
2016 have the potential to meet all of your enterprise storage needs
without breaking the bank.
